Physiological Plasticity Is Important for Maintaining Sugarcane Growth under Water Deficit

Abstract

The water availability at early phenological stages is critical for crop establishment and sugarcane varieties show differential performance under drought. Herein, we evaluated the relative importance of morphological and physiological plasticity of young sugarcane plants grown under water deficit, testing the hypothesis that high phenotypic plasticity is associated with drought tolerance. IACSP95-5000 is a high yielding genotype and IACSP94-2094 has good performance under water limiting environments. Plants were grown in rhizotrons for 35 days under three water availabilities: high (soil water matric potential [Ψm] higher than -20 kPa); intermediate (Ψm reached -65 and -90 kPa at the end of experimental period) and low (Ψm reached values lower than -150 kPa). Our data revealed that morphological and physiological responses of sugarcane to drought are dependent on genotype and intensity of water deficit. In general, IACSP95-5000 showed higher physiological plasticity given by leaf gas exchange and photochemical traits, whereas IACSP94-2094 showed higher morphological plasticity determined by changes in leaf area (LA) and specific LA. As IACSP94-2094 accumulated less biomass than IACSP95-5000 under varying water availability, it is suggested that high morphological plasticity does not always represent an effective advantage to maintain plant growth under water deficit. In addition, our results revealed that sugarcane varieties face water deficit using distinct strategies based on physiological or morphological changes. When the effectiveness of those changes in maintaining plant growth under low water availability is taken into account, our results indicate that the physiological plasticity is more important than the morphological one in young sugarcane plants.

Irrigation management based on reference evapotranspiration for pre-sprouted plantlets of sugarcane cultivars

“…'IACSP97-4039' is the most indicated to restrictive environments with poor soils and water deficit (Gomes 2013). Marchiori et al (2017) verified that morphological and physiological traits are both cultivarand drought-dependent. Thus, it is important to understand cultivar response to different water deficit intensities.…”

“…The secondary treatments (subplots) were the plastic trays containing one cultivar each: IAC91-1099, IACSP95-5000 and IACSP97-4039. 'IACSP95-5000' is recommended for fertile soils and some studies reported results that suggest it is susceptible to water deficit when compared to others (Machado et al 2009;Ribeiro et al 2013;Boaretto et al 2014), although Marchiori et al (2017) verified that it has some resistance to mild water stress. 'IAC91-1099' has higher plasticity than 'IACSP95-5000' concerning crop environment and it is suited for planting in regions with higher water deficit compared to 'IACSP95-5000' (Landell et al 2007).…”

The Assessment and the Within-Plant Variation of the Morpho-Physiological Traits and VOCs Profile in Endemic and Rare Salvia ceratophylloides Ard. (Lamiaceae)

“…The physiological plasticity has a low cost and more rapid response with respect to the cost-expensive morphological plasticity, allowing the expression of the most adequate plant phenotype in response to the variable climatic conditions. For example, the plant physiological plasticity is strictly related to an enhanced ability to colonize gaps and open areas and, hence, exploiting the transient environmental resources at low cost by short-term adjustments, such as plant acclimatization [ 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 , 57 , 58 , 59 , 60 ]. Conversely, the plant morphological plasticity is more functional for the plant adaptation in the long-term and probably useful for growing in forest understories [ 57 , 61 ].…”

Foliar-applied glycine betaine minimizes drought stress-related impact to gas exchange and the photochemical efficiency of PSII in sugarcane

“…In this study we sought to understand how the GB exogenous action occurs on the physiological mechanisms of tolerance to dehydration in young plants of sugarcane. This stage was chosen because it is considered to be the most susceptible to water deficiency, in addition to having the greatest changes in its metabolic activities and physiological plasticity in culture (Marchiori et al 2017;Endres et al 2019).…”

“…However, drought stress is one of the factors that most compromises sugarcane development and final yield, particularly in tropical regions (Jangpromma et al 2012;Silva et al 2013). Drought reduces primary growth and negatively interferes with physiological yield processes, such as gas exchange and photochemical efficiency of PSII (Sales et al 2013;Zivcak et al 2013;Marchiori et al 2017;Silva et al 2018).…”